Purification of phenol sulfides and preparation of metallic salts thereof



Patented Jan. 18, late AND PREPARATION "OF 'META'IJIZIC THEREOF Harry E.Albe'rt, Akron, (iliimxassignortil-T1165 Fireston'e- "Tire Ai ,Ttubberi -('}om1 )any-,. Akron;

Uliio; incorporationof Ohio I No. Drawing. Application M2y23j1946-Q I SeriaI'No. 671,908

I This invention relates to an improved' process ofproducing metal salts of phenol sulfides; and especially tin salts thereof. "Morejparticularly, the," invention relatesto-the preparationof such metal salts-from a'reacti'on product of a phenol arid-asuliiirchloride; which reaction product-contains-sulfur, present in the free 'state'andjorin p'olysulfide'linkages, and the extraction of the freeand/orpolysulfide sulfur-therefrom as a'step in the-production' of'th'e metal salt:

The metalfsal'tsof phenol sulfides have been found useful in the treatment of petroleum oils and rubber and rubber-likem'aterials', etc. For suchpurposesa colorless salt of 1a phenol sulfide as well 'asa purer salt is preferred to the highly colored impure salts now available.

If crude phenol sulfides--12 e., "phenol sulfi'de which containssulfurtn polysulfide linkages or m the free state'are used' in the preparation of salts-of metals; such as tin orantimony; etc, the sulfur impurities in the phenol sulfides cause the products to be colored. For example, in the case of stannous' salts," a brick-red product. isobtained'. The invention, thereforalias particular value in the preparation-ofsalts of tin and" other'metals whose sulfides are highly colored although it is not limited thereto.

"According to this invention, the metal salt is obtained substantially pure. Phenol and'a sulfur chlorideefl gzgsulfur monochloride or sulfur dichlorid e-are reacted to produce a phenol sulfide which contains free'and/or polysulfide sulfur, and

this is treated with'aqueous alkali metal sulfite oralkaline earth metal sulfite to remove any: free andpolysu'lfide' sulfur which may be present before reacting with a salt of the metal-whose phenol sulfide is ultimately desired. The aqueous suIfite-may be used either to extract the phenol sulfidfe in sol'id'form or to extract a solution of thephe'nol sulfide in an inert organic solvent. After extraction with the solute, the sulfite solution is preferably, although not necessarily, separated from the phenol-sulfide before coriyersiontothe metal salt. A preferred process of'producing a -metal-salt of a phenol sulfide involves extracti'onof the solid, water-insoluble, free and/or polysulfide sulf-urcontaining reaction product of phenol and sulfur chloride with a water solutionofiarralkali metal sul fite followed by Washing and? drying; ancl 'then preparation" of an anhydrous alkali or'alkali ne earth metal salt of theextracted phenol sulfide by reaction with'the corresponding. alcoholateor hydroxide with resultant reaction with;the chloride; of the, metal whose phenol sul fide::is rdesired..- To produce the stannous salt; it.

Q'Glaims; (01. 266429;)

2 is. preferable; to: 1use-;the: stannous; chloride inlan inert. solvent,- 811011138251 absolute; alcohol; ormethanol; RlifipBiIfiiiliOlL-Qf, the stannous, salt .in an aqueous mediumjs;;possib1e;. :but; some hydrolysis of thestannoussalt. almost always occurs. -.Although the: examples relate more: particularly to the preparation of stannous salts, it is obvious that; ot-herwsalts be'isimila-rlm prepared byusingachlo-rides; of other:metals,.;suchas, antimony, bismutmzinc cadmium lead,;etc.

The followin examples illustrate the, ,invention:

I ,1 EXAMPLE 1 The stannouasalt ofiAa-tert-amylphenol sulfide One hundred; gramszof crudefil-tert-amylphenol sulfides. prepared by? reactina- 4.-tert-amylphe nol with: sulfur: dichloride, were: treated in: solidform with. :a. solutionofr 30;grams .of sodium sulfite: in 6.00- mil-liliters ofwater: ton "11510111" on the steam bath; The sulfite-tsolutioni was; removed and: the extracted sulfide washedta-nd, dried-., Twelve and nine-,t'enths rams .ofz sodium. were; dissolyedr. in 500 cubic centimeters: of: absolutesmethanol; and the; extractedra-nd adried. 4-tert-amylphenol sulfide:addeidztoithe-resulting solution. Tothis a methanol-.: -solution of 5.9'.'51 -grams .of anhydrous stann-ous chloride was-added. A whiteprecip tate. of; .thestannous .salt of 4.-ttert-.a-mylphenol sulfide was? obtained which weighed 92.0.-- grams after drying. It=m-elts= to a: clear..-:a.mher liquidat 260.-.280?:C..

Ther stannous salt, of this, phenol: sulfide, similarly; prepared-5- but, omitting theextraction with sodium sulfite isbriclg red.

'"EXKMPLEZ" The, stmmotzs. ,saltof diphenol. sulfide,

Ten grams oi crude diphenol sulfide-prepared by reacting phenol? withzsulfurdichloride were digested'sin 1 00 milliliters of 5I'per cen-t aqueous sodium: sulfite for' l 'hour on-a steam,..bath. The product was filteredi-andt was-hed after cooling.- to

. roomtemperature.. The precipitateewascrystalpowder-turning-brown-on heating to 220-230 C.,.

melting to a clear liquid at 240-245 C. and decomposing at 255-260" C.

EXAMPLE 3 The stannous salt of,4 tert-butyl-3-methylphenol sulfide Thirty-five and seven-tenths grams of crude l-tert-butyl-3-methylphenol sulfide prepared by reacting 4-tert-butyl-S-methylphenol with sulfur dichloride were dissolved in 70lmilliliters 'of.ben-

zene, and this solution was extracted for hour with 300 milliliters of 5 per cent aqueous solution of sodium sulfite, with the help of'mecham'cal agitation. The benzene solution was separated off and washed with 400 cubic centimeters of water, After drying, this benzene-solution was added to a solution prepared by dissolving 4.6 grams of metallic sodium in 150 milliliters of absolute methanol. After standing for 5 minutes,

a solution of 19 grams of anhydrous stannous chloride in 50 millilitersof absolutemethanol was slowly added. "A white precipitate of the stannous salt of 4-tert-butyl 3-methylphenol sulfide was formed which was filtered and found to weigh 20 grams after drying. An additional amount of product was obtained by evaporation of the solvent. V

The dry precipitate waslight yellow in color and did not melt on heating. It gradually darkened in color as the temperature was raised and Four and seven-tenthsgrams of the resulting product were dissolved in aanhydrous methanol solution of sodium methanoliprepared by dissolving 0.46 gram of sodium me'talin-'500 milliliters of anhydrous methanol. The resulting'reaction 'mixturewas refluxed for about 3 hours, and then asolution of 1.5 grams of antimony trichloride in 100 milliliters'of absolutemethanol wa's'added slowly during stirring. The methanol was then distilled off and sodium-dried benzene added to dissolve the product. A small amount of benzene was distilled offtoreinovethe residual methanol. After cooling, the solu'tion was filtered to remove the sodium chloridepresent in the reaction product. Evaporation of the benzene solution gave a light yellow product weighing 5.3 grams. It melted at 225-235, C. with-decomposition to a clear dark green liquid,

The. separation of the sodium sulfite'solution be.- fore the preparation; of the'tin or othervsalt is not absolutely necessary although separation is the preferred procedure. In the following example a product of improved color; but not colorless, is obtained by preparation of. the tin salt in the presence of the sulfite solution.

. EXAMPLEYSJV stannous salt of d'iphenoz sulfide Twenty-two grams of crude diphenol. sulfide, prepared by reacting phenol withsulfur dichloride in ethylene dichloride, were treated with a solution of? grams ofsodium sulfite in 200 milliliters of water for 1 hour at room temperature. A solution of 8 grams of sodium hydroxide in milliliters of water was added, and this was followed by the slow addition of 19 grams of anhydrous stannous chloride in milliliters of water. Filtering and drying the resulting precipitate gave 34.5 grams of a light brownish-yellow product. Using the same procedure without the sodium sulfite treatment, a red precipitate was obtained.

It is to be understood that the details of the specific processes are not essential to the invention, that the metal salts may be prepared by other processes, and that the processes of the r examples are generally applicable to the preparation of metal salts so that the phenol sulfide salts of other metals may be formed by the processes dis-closed, and that other variations fite of the class consisting of alkali metal sulfitesand alkaline earth metal sulfites and thereby removing at least some of said impurity,

2. The process of purifying a phenol sulfide which contains impurity of the class consisting of free sulfur and polysulfide sulfur resulting from the reaction of the phenol and a sulfur chloride, which process comprises extracting the phenol sulfide in solid form with an aqueous solution of a sulfite of the class consisting of alkali metal sulfites and alkaline earth metal sulfites and thereby removing at least some of said impurity.' 3

3. The process of purifying a phenol sulfide which contains impurity of the class consisting of free sulfur and polysulfide sulfur resulting H from the reaction of the Phenol and a sulfur chloride, which process comprises extracting the phenol sulfide in solution in an inert solvent immiscible with water, with an aqueous solution of a sulfite of the class consisting of alkali metal sulfites and alkaline earth metal sulfites and thereby removing at least some of said impurity.

4. The process of purifying a phenol sulfide obtained by reacting a phenol with a sulfur chloride, comprising extracting the phenol sulfide with an aqueous solution of a sulfite of the class consisting of alkali metal sulfites and alkaline earth metal sulfites. 5. The method of purifying a phenol sulfide which contains free sulfur asan impurity, which comprises extracting the phenol sulfide withvan aqueous solution of a sulfite of the class consisting of alkali metal sulfites and alkaline earth metal sulfites to dissolve the free sulfur from the phenol sulfide.

6. The process of purifying a phenol which contains as an impurity polysulfide sulfur resulting from the reaction of the phenol and a sulfur chloride, which comprises extracting the phenol sulfide with an aqueous solution of a sulfite of the class consisting of alkali metal sulfites and alkaline earth metal sulfites to dissolve the polysulfide sulfur from the phenol sulfide. I

7. The process of producing the stannous salt of a phenol sulfide which comprises reacting a phenol with a sulfur chloride to produce a phtnol sulfide which contains impurity of the class consisting of free sulfur and polysulfide sulfur, extracting the phenol sulfide in solid form with an aqueous solution of an alkali metal sulfite to dissolve impurity therefrom, and without separation of the resulting sulfite solution converting the phenol-sulfide to the stannous salt thereof.

8. The process of producing metal salt of a phenol sulfide, which comprises reacting a phenol with a.. sulfur chloride to produce a phenol sulfide containing impurity of the class consisting of free sulfur and polysulfide sulfur, extracting the phenol sulfide with an aqueous solution of an alkali metal sulfite to dissolve the impurity therefrompand without separation of the resulting sulfit'e solution converting the phenol sulfide to a metal salt thereof.

9. The process of producing a purified phenol sulfide which comprises reacting the phenol with a sulfur chloride and treating the product with an aqueous solution of sodium sulfite.

HARRY E. ALBERT.

REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS OTHER REFERENCES Bichowsky, Chem. Abstracts, vol. 17, p, 3641 (1923).

Watson et al., Chem. Abstracts, vol. 18, p. 1255 (1924).

Watson et al., Chem. Abstracts, vol. 20, p, 1363 (1926). 

